Many people who have pets, especially pet cats, choose, or may be required, to keep their pets inside at all times. An inside pet needs a place to deposit solid and liquid waste (feces and urine). This need has been met by the provision of a container known as a litter box. The basic requirements of a litter box are that it is configured to effectively hold the particulate material called litter, that it provides a place that is sufficiently attractive to the pet so that the pet deposits its waste in the litter, and that it can be cleaned to remove the deposited waste without excessive effort. While designers of animal litter boxes have focused on achieving these objectives, currently available litter box designs require more effort to keep clean them clean than is desirable from the pet owner's perspective. A clean litter box is not only important for keeping an animal healthy, it is also necessary for maintaining the litter box and its indoor location in an odor-free and sanitary condition.
There are currently available many types of containers of the sort typically referred to as litter boxes available from which pet owners can select to use for their indoor pets. While most of these containers are used by cats, they may be used by any indoor pet that can be trained to deposit its waste in a container. Such containers range from a very simple open top basin costing under $10 to elaborate arrangements that attempt to conceal or disguise the function of the structure costing in excess of $100. A simulated planter holding litter that can be accessed by the pet, complete with an artificial palm tree, is an example of one of these complex structures. Such a structure can be difficult to keep clean. The basin type of container, while inexpensive and easy to use from the pet's perspective, has drawbacks. Cats, in particular, dig in the litter material and cover their waste, which results in the litter material being spread outside the container unless the container walls are high enough to prevent this. Waste and soiled litter must be removed from the container by hand with a scoop, which is a tedious, dirty job. The simulated planter or other similarly enclosed types of litter containers, such as, for example, the dome covered litter container available under the BOODA brand and from other sources, prevent the spread of litter beyond the container, but present the same sorts of challenges to cleaning and maintaining the litter in a clean and sanitary condition. In U.S. Pat. Nos. 7,849,818 and 7,856,945, for example, Matsuo et al show and describe an animal litter box with a rotatably movable hood disposed above a removable evacuation container that allows the litter box to be used in an open or closed condition.
The prior art includes many litter container designs with features intended to facilitate cleaning. A simple solution for maintaining a clean litter container is to remove and dispose of all of the litter and clean the container before adding new litter every day. While this method very effectively keeps the container clean and sanitary, the appropriate disposal of used litter and the replacement cost of new litter must be considered. Most pet owners whose pets live indoors and use litter containers try to clean and reuse any reusable litter rather than discarding the litter each time the litter container is cleaned. The removal of only the soiled litter material and the reuse of the remaining litter material, which is made easier by the types of clumping litter material currently available, is the most widely used approach. A common approach manually removes solid waste and soiled litter with a slotted scoop implement. The soiled litter must be removed to another container or bag, which increases the likelihood of spills. With this approach, the litter container itself is typically not cleaned or sanitized very often. One type of litter container, such as that shown in U.S. Pat. No. 7,762,213 to Cook et al, for example, has a system that automatically removes waste after the animal has deposited it in the litter and includes sensors and a motorized rake/scoop element that is activated to remove the soiled litter. These systems tend to be noisy and can startle the animal before it has finished depositing its waste, which is likely to result in extra manual cleanup and a frightened animal that will not use the litter container.
Litter containers that provide a sifting feature to separate reusable litter from soiled litter so that the pet owner does not have to manually remove the litter are disclosed in the art. U.S. Pat. No. 5,517,947 to Christman, for example, describes a litter box with rectangular nested trays that include a sifting feature formed from a series of slots along one sidewall of each tray to allow reusable litter to pass from one tray to the other while the soiled litter is separated out for disposal. This litter container, while an improvement over other available litter containers, still can require quite a bit of manual effort by the pet owner to remove the soiled litter, especially the wet soiled litter. Carlson, in U.S. Pat. No. 4,505,226, describes an animal litter box that includes a pair of substantially identical nesting containers with grids at the bottoms sized to permit the passage of litter while retaining solid waste. A separate removable retaining edge attaches to the upper edge of these rectangular containers to keep litter in the box as the animal scratches in the litter material while depositing its waste. Each container also includes a separate false bottom piece with a peripheral rubber gasket that covers the apertures and provides a surface to which wetted litter can adhere. The false bottom piece must be mechanically worked to remove the wetted litter material. While this arrangement may be easier to clean than many available litter container designs, it also has some drawbacks. During cleaning, the retaining edge structure and then the false bottom piece must be removed before the litter can pass through the grid to the nested container below. Depending on how much litter is covering the false bottom piece, quite a bit of effort may be required to move the false bottom so the grid is exposed, especially if the rubber gasket becomes wet or otherwise sticks to the container. The spillage of soiled litter material outside the container as the false bottom is removed is a very real possibility. In addition, the vibrating and other mechanical working described to be required to remove the adhered wet soiled litter from the false bottom could well be beyond the physical capabilities of many pet owners.
The prior art, therefore, does not disclose an animal litter container for indoor use by an animal that is configured to minimize contact with soiled litter while facilitating cleaning of the container, making it truly easy for virtually all pet owners to clean the litter container and maintain it in a clean and sanitary condition without undue effort.